Gaggia Classic Boiler Replacement

This article documents the replacement of a boiler from a Gaggia Classic. It is a 2005 model, and whilst it has generally been serviced well over the years, the boiler has, over the past year become unserviceable. This is mostly in part due to corrosion from the aluminium dispersion plate that has become welded to the group head, and despite removing the boiler entirely and using some fairly industrious methods to separate the two, the results have merely been to damage the dispersion plate further. 

I had therefore made the decision to replace the entire boiler; which was also in a fairly bad way, and also the group head, dispersion plate and all the associated seals. The following shows images of the work necessary and the improved performance. 


All the wires were labelled ready for the loom to be removed. It’s easy to muddle up cables, so to save confusion later, it’s worth labelling each cable if the loom is to be removed entirely. 


Previous damage to the boiler had resulted in an element pin being broken off. This was patched by soldering directly to the element. 

Once all the components have been removed the case could be cleaned up and a new plug crimped onto the loom for the broken pin. 

Above shows the condition of the vibratory pump bush that prevents too much noise and case vibration. This was replaced with new, and the pipes removed and soaked in Cafiza to remove the stains and residue. The pump and rubber bush is held on to a metal plate via a clip that is then screwed to the case. 

Opening the old boiler was necessary to remove the 48mm copper boiler pipe inside. It was also interesting to see what condition the internals were left in after a period of neglect. The boiler was opened with an angle grinder cutting through the bolts as these were firmly seized. 

Assembling the new boiler.

Assembled Boiler using the Italian made IMS 55mm GA200IM Competition Shower Screen and Silicon Gasket

Assembled Boiler using the Italian made IMS 55mm GA200IM Competition Shower Screen and Silicon Gasket


Ready to be rebuilt. 

Cleaned and reassembled ready for the dreaded leak test ! 

Up and Running !

Steam Power